How to Turn up a Turbo


1. Purchase a twist-type manual boost controller. These in-line check valves have a spring mechanism inside which, when you twist the MBC (manual boost controller) body together, receives more pre-load to keep the valve shut longer.
2. Locate the waste gate diaphragm on the base of the turbocharger. It will look like a small flying saucer with an armature coming out of one end and a rubber vacuum line (boost sensor line) coming out of the top. Follow it back to the intake manifold or pressure tube.
3. Cut a 2-inch section from the boost sensor line. Where you make the cut isn't important; just cut where you'll have easy access for later adjustment.
4. Screw the body of your MBC counter-clockwise until the ends are hanging together by just two threads. This will release the pre-load on your spring to prevent an overboost the first time you fire the engine.
5. Slip a hose clamp over the turbo side of your sensor line and plug the MBC into the line. Some MBCs will have an arrow on the exterior to indicate the turbo side; on others you'll find 'boost' or 'turbo' printed.
6. Slip another hose clamp over the intake side of the line, and plug the line into the MBC. Tighten the hose on the turbo side hose clamp completely, but do not completely tighten the intake side.
7. Start the car and slowly raise the rpm while closely monitoring the boost gauge. At this point, it should read no higher than it did stock.
8. Hold the rpm at about 4,000 rpm while an assistant slowly screws the body of the MBC together. Keep a close eye on your boost gauge.
9. Once you have the boost set at your desired level, have your assistant tighten down the intake-side hose clamp and MBC lock nut, if so equipped.